Patent EA-000604-B1 (EA)
Title: Refractory assemblies
Inventor: RICHARD FRANCOIS-NOEL
IPC: B22D41/36
Filed: 1997-10-15
Abstract: 1. Set of refractory assemblies (8, 12, 30, 32, 42, 48, 50, 60), comprising at least two refractory assemblies (8, 12, 30, 32, 42, 48, 50, 60), which is capable of being used between an upstream container (2) and a downstream container (10) of a plant for transferring liquid metal, in particular steel, comprising: a tapping spout (28) via which the metal flows from the upstream container (2) into the downstream container (10), each refractory assembly (8, 12, 30, 32, 42, 48, 50, 60) of the tapping spout (28) having at least one surface forming a mating surface (22) with a corresponding surface of an adjacent refractory assembly (8, 12, 30, 32, 42, 48, 50, 60); a flow regulator (26) for regulating the flow of liquid metal through the tapping spout (28); a shroud channel (34) placed around the tapping spout (28) near at least one mating surface (22) between refractory assemblies (8, 12, 30, 32, 42, 48, 50, 60) and having an inlet (38) capable of allowing the intake of a fluid; the said at least two refractory assemblies comprising means capable of forming the said shroud channel; characterized in that the said shroud channel (34) has an outlet (40) capable of allowing the fluid to escape to the outside of the plant. 2. Set of refractory assemblies according to Claim 1, characterized in that the shroud channel (34) has an inlet (38) at one end and an outlet (40) at the other end. 3. Set of refractory assemblies according to Claim 2, characterized in that the shroud channel (34) is linear and continuous. 4. Set of refractory assemblies according to any one of the preceding Claims, comprising two refractory assemblies, characterized in that the inlet (38) of the shroud channel (34) is located on one of these assemblies and that the outlet (40) of the shroud channel (34) is located on the other. 5. Set of refractory assemblies according to any one of the preceding Claims, characterized in that the inlet (38) of the shroud channel (34) and its outlet (40) are provided on a single refractory assembly, the entirety of the shroud channel (34) being made in this refractory assembly. 6. Set of refractory assemblies according to any one of Claims 1 to 3, characterized in that the shroud channel (34) runs through several mating surfaces (22) of the tapping spout (28) in succession, the continuity of the shroud channel (34) being provided by corresponding communications of the said channel at the mating surfaces (22). 7. Set of refractory assemblies according to any one of the preceding Claims, characterized in that a calibrated head loss (44) terminated by a venting outlet (46) is connected to the outlet (40) of the shroud channel (34) outside the set of refractory assemblies. 8. Set of refractory assemblies according to any one of Claims 1 to 6, characterized in that a calibrated head loss (44) terminated by an venting outlet (46) is connected to the outlet (40) of the shroud channel (34) and consists of a duct of small cross-section and of suitable length made within the actual refractory assembly. 9. Set of refractory assemblies according to any one of Claims 1-8, in which two or more successive refractory assemblies in the form of plates (48, 50) constitute a movable slide gate valve, characterized in that at least one of the plates (48) has a first U-shaped part of the shroud channel (34), the arms of which are aligned with the movement of the slide gate valve, a second plate (50), adjacent to the previous one, has a second U-shaped part of the shroud channel (34), opposite the previous one, one arm of the U of one the plates (48) is partially superposed on one arm of the U of the other plate (50) for at least certain positions of the slide gate valve, so as to ensure continuity of the shroud channel, the arms of the shroud channel which are opposite the superposed arms are offset so that there is no superposition between them, whatever the position of the slide gate valve, and the parts of the shroud channel are capable of being connected together and to the adjacent refractory assemblies so as to form a continuous linear shroud channel (34). 10. Refractory assembly (42) capable of being used in a set of refractory assemblies according to any one of the preceding Claims. 11. Refractory assembly (42) capable of being used in a set of refractory assemblies according to Claim 9, characterized in that the TJ-shaped part of the shroud channel (34) is placed non-symmetrically with respect to the tapping spout (28). 12. Plant for transferring liquid metal, in particular steel, between an upstream container (2) and a downstream container (10), characterized in that it comprises a set of refractory assemblies according to any one of Claims 1 to 9. 13. Plant for transferring liquid metal according to Claim 12, characterized in that it comprises means capable of introducing a sealing agent into the shroud channel (34). 14. Method of regulating the supply of inert gas in a plant for transferring liquid metal according to either of Claims 12 and 13, characterized in that a flow of inert gas is injected into the shroud channel (34), the flow being set at a high enough value for an excess of inert gas to escape via the outlet (40) whatever the flow rate of inert gas drawn into the tapping spout. 15. Method of regulating the supply of inert gas in a plant for transferring liquid metal according to either of Claims 12 and 13, characterized in that a flow of inert gas is injected into the shroud channel (34); the pressure of the inert gas in the shroud channel is measured; the flow rate of inert gas injected into the shroud channel is regulated to a set value; the flow rate of inert gas at the venting outlet (46) is calculated; the set value of the flow rate of inert gas injected into the shroud channel is adjusted in such a way that the flow rate of inert gas at the venting outlet is always positive. 16. Method according to Claim 15, characterized in that the flow rate of inert gas drawn into the tapping spout (28) is determined by the difference between the flow rate of inert gas injected into the shroud channel and the flow rate of inert gas at the venting outlet (46); a sealing agent is introduced into the shroud channel when the said flow rate of inert gas drawn into the tapping spout (28) exceeds a permitted limit.